In recent year, air-flow mats and A/C cloths that evaporate sweat from a human body by an air flow have been put into practice (e.g. see Patent Document 1 and Patent Document 2). For example, an A/C cloth is de of a material that is less permeable to the air, and two fan-mounting parts for mounting fans are provided in the lower back part of the A/C cloth. By mounting fans to the fan-mounting parts and powering them, a large amount of fresh air is taken from the outside into the A/C cloth. The fresh air taken in the A/C cloth flows upward parallel to the human body and is then discharged from, for example, holes of a collar and cuffs. While flowing inside the A/C cloth, the fresh air evaporates sweat from the human body. The body surface temperature can thus be decreased due to the heat of the evaporation (e.g. see Patent Document 3).
Next, a method for producing an A/C cloth will be described. In the following description, an A/C working cloth is taken as an example of an A/C cloth. Prior to the description, a method for producing a typical working cloth is briefly described. To produce a typical working cloth, first, the fabric parts thereof are prepared by cutting fabric according to a pattern of the working cloth. A typical working cloth requires approximately as many as a dozen of fabric parts. Then, a fastener, buttons and the like are attached to predetermined fabric parts. Thereafter, the fabric parts are sewn together into the typical working cloth.
A major difference between a method for producing an A/C cloth and a method for producing a typical working cloth is that the method for producing an A/C cloth involves a step of providing a fan-mounting part for mounting a fan to a fabric part that corresponds to the lower back part of the A/C cloth. As used herein, a sheet having a fan-mounting part refers to a sheet member such as fabric or a fabric part in which a fan-mounting part is provided. There are basically two methods for producing an A/C cloth. One method is to directly form a fan-mounting part in a fabric part itself that corresponds to the lower back part of an A/C cloth. The other method involves forming a sheet having a fan-mounting part beforehand in which the fan-mounting part is provided not in a fabric part of an A/C cloth but in a sheet member such as a small fabric, and sewing it to a fabric part that corresponds to the lower back part of the A/C cloth. In the following description, the former method is referred to as an own-sheet method, and the latter method as a separate-sheet method.
The own-sheet method requires forming the fan-mounting part in the fabric part in a sewing site, while the outer appearance provokes a less sense of inconsistency since the fabric part is a part of the fabric of the A/C cloth itself. In contrast, the separate-sheet method allows mass production of the sheet having a fan-mounting part in a different place other than a sewing site, for example, by using a rectangular fabric with an adequate size according to the size of the fan. The mass-produced sheet having the fan-mounting part allows normal sewing factories to produce the A/C cloth without any equipment or skill required for processing the fan-mounting part. From an economic viewpoint, it is not rational to use the same fabric as that of the A/C cloth itself, but it is desirable to use fabric of a different material. In such cases, since the fabric of the A/C cloth is different from the fabric of the sheet having the fan-mounting part, the outer appearance may provoke a sense of inconsistency. However, it is advantageous in the production cost.
In almost all A/C cloths, fans are attached in two locations in the back part. However, since such fans cool the low back too much and are disturbing when driving a car or the like, it has been often required to attach fans right in the sides of the body part. FIG. 12 is a schematic side view of a typical working cloth. In a typical working cloth, fabric parts 200 are sewn together right in the sides as illustrated in FIG. 12. In the figure, seams 210 formed by the sewing are illustrated by the dashed lines. Similar to typical working cloths, fabric parts 200 are sewn together right in the sides of A/C cloths. Therefore, it is difficult to form fan-mounting parts in the sewn parts by the own-sheet method. In contrast, it is possible to attach fans right in the sides by the separate-sheet method since the sheets having the fan-mounting part can be readily attached over adjacent fabric parts 200.
No matter which method is used for producing an air-flow mat or an A/C cloth between the own-sheet method and the separate-sheet method, it is required to firmly attach the fan to the sheet member so that the air does not leak through the fan-mounting part in order to improve the air-conditioning performance. On the other hand, it is required that the fan is readily detachable from the sheet member by a user for washing the air-flow mat or the A/C cloth.
For this reason, it is desirable to use a fan having the structure as disclosed in FIG. 12 of Patent Document 2 for A/C cloths and the like. Such fans include a fan body and a ring engaging member for mounting the fan body on a sheet member. The fan body includes a hollow cylinder part and a flange part that protrudes from the upper end of the cylinder part in a direction approximately perpendicular to the side face of the cylinder part. The fan is mounted on the sheet member by fitting the ring engaging member on the outer side of the cylinder part and thereby tucking the edge part around an open hole of the sheet member between the underside of the flange part and the end face of the ring engaging member opposed to the flange part and engaging an engaging piece formed in the cylinder part with a protrusion formed in the ring engaging member.
If the fan-mounting part is constituted by only the sheet member with an open hole for mounting the fan, the fan readily comes off from the sheet member due to a great force applied to the fan since the sheet member used in A/C cloths and the like is stretchable. To avoid this, the Patent Document 2 proposes to use the fan-mounting part that has an open hole for mounting the fan and includes a non-stretchable material disposed in the edge part around the open hole of the sheet member. Specifically, the fan-mounting part with the non-stretchable material is produced as follows. First, a hole is formed at a predetermined location in the sheet member, and the part of the sheet member around the hole is folded to the back. Then, a non-stretchable ring material is inserted in the overlapped part of the sheet member that was formed by the folding. Thereafter, a fabric is patched to the back side of the part of the sheet member in which the non-stretchable material is inserted, and the fabric is sewn to the sheet member with a thread. In this way, the open hole is formed, and the non-stretchable material is stitched around the open hole.